Hair Graft Calculator

This calculator gives a rough idea of how many grafts a hair transplant might involve. Choose the pattern closest to your hair loss, the areas you would like restored, how full you would like them to look and your hair type, and it shows an estimated range.

It is an estimate only, not a clinical assessment. The independent clinician decides the number of grafts, and whether a hair transplant suits you, when they assess you. Longevita arranges hair transplants with independent clinicians in Istanbul, Turkey, and does not give medical advice.

The estimate multiplies the area to be restored, in square centimetres, by a target density: the number of grafts placed in each square centimetre. One graft is one follicular unit, a natural group of one to four hairs.

• Area: no published study measures the bald area at each Norwood stage, so we work it out from one that gives graft numbers by stage. Bernstein and Rassman list the grafts needed for a complete restoration at each stage from Norwood III, and recommend 20 to 25 grafts per square centimetre for large sessions; dividing one by the other gives each stage’s area. Norwood III comes to about 45 to 60 cm² and Norwood VII to about 180 to 280 cm², within the roughly 300 cm² of scalp at risk of balding that Garg and Garg describe. The hairline and frontal areas are sized from the measurements in Marwah and Mysore.
• Density: natural is 20 to 25 grafts per cm² (Bernstein and Rassman), medium 30 to 40 (Garg and Garg; Nakatsui and colleagues) and full 40 to 50, the range described as dense packing (Unger; the PRECISE scale).
• Hair type: thick, curly and afro-textured hair covers more scalp per graft, so a similar look can take fewer grafts (ISHRS; Bernstein and Rassman). The calculator places these hair types in the lower half of the chosen density’s range, and fine, straight hair in the upper half. It never goes outside that range.
• Female pattern: Ludwig describes the thinning on top as covering the area of advanced male hair loss without the front hairline, each grade thinner than the last. The PRECISE scale counts a partly thinned area in proportion to the thinning. How much thinning each grade stands for is our own reading, so the estimates for women are the least certain.
• Hairs: a graft holds 1.8 to 2.1 hairs on average, from two studies of 580 and 820 men (Chouhan and colleagues, 2019a; 2019b).
• Sessions: about 4,000 grafts is a common upper limit for one session. In the ISHRS 2022 Practice Census, the average first session was 2,176 grafts, and 1% of member surgeons averaged 4,000 or more. A session of more than 3,000 grafts is often called a megasession (Gabel).

Real scalps differ in size and shape, and clinicians often place grafts more densely at the front than at the crown, so your own number may fall outside the range. Only the independent clinician’s assessment gives a number for you.